1. Field of the Invention
The present invention relates to a dictionary data registration apparatus for an image recognition, a method therefor, and a program.
2. Description of the Related Art
Conventionally, a face recognition technique has been known in which personal identification is performed by extracting a face region from an image including a human face, and comparing the extracted facial image with a facial image of a particular person which is registered in advance. The face recognition technique is used for a purpose of security, for example, when a person on a camera is authenticated as a registered person, the person is allowed to enter into an office. On the other hand, there is a request to utilize this technique for searching photographs on which the same person is captured. In the former purpose, recognition can be performed with high accuracy by setting a limitation on conditions such as an orientation and a size of a face and illumination when capturing an image of a person. However, in the latter case, there is an issue that image-capturing conditions of the person cover a broad range and recognition accuracy may be reduced. For example, among photographs in which orientations and expressions of the face, and illuminations during image-capturing are different, even the same person in the photographs was sometimes erroneously determined as another person.
To solve such an issue, a method for previously registering a plurality of facial images corresponding to various conditions and performing recognitions is discussed. For example, Japanese Patent Application Laid-Open No. 2007-249588 discusses a method for improving recognition accuracy by previously registering faces in various states such as looking-up faces, bearded faces, open-mouth faces and so forth from input moving images. Japanese Patent Application Laid-Open No. 2009-25899 discusses a method in which the recognition accuracy is improved by previously registering a plurality of facial images with different face orientations.
However, when an attempt is made to register images with different combinations of the conditions such as orientations and expressions of faces, and illuminations, the number of facial images to be registered will become extremely plenty. Further, when many images are registered, it is necessary to perform matching with many registered images when recognition processing is performed, and accordingly, throughput will become large.